I wrote in the Preliminaries, at the end of section 8, of a ‘preferred [Socratic] account of the nature of knowledge to which Plato subscribes’. This ‘preferred account’ of knowledge is – unexcitingly – the one that Socrates and Theaetetus reach at the end of the Theaetetus: that knowledge is true belief together with a logos (a definition, or more generally a description, or a list of features) which will somehow definitively mark off the thing known from other things. This account is itself a close relation of the one Socrates offers in the Meno (knowledge as true belief ‘bound’ by calculation, logismos, of the cause), and is equally, and similarly, problematical. How exactly will the ‘account’, the logos, be able to add anything definitive to the belief, which if true must already be successfully referring to whatever it claims to be about?

Not a few interpreters have taken this problem to be fatal to the account, so that for them the Theaetetus will end with no solution at all: either because the dialogue was designed as a dialectical exercise, or alternatively, on the more standard view, because it was designed to show that there is no way forward without Platonic forms – to which, allegedly, there is no overt reference in the Theaetetus.